Having some crashes

You may remember my recent thread about an upgrade.. well i decided to, Here are the specs:

Power Supply: XIGMATEK MC NRP-MC751 750W ATX12V

Motherboard: ASUS P5N-D LGA 775 NVIDIA nForce 750i SLI ATX Intel

Processor: Intel Core 2 Duo E6750 Conroe 2.66GHz LGA 775 65W Dual-Core

Graphics Card: EVGA 01G-P3-1281-AR GeForce GTX 285 1GB 512-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported

Ram: SUPER TALENT 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

HDD: Western Digital Caviar SE16 WD2500KS 250GB 7200 RPM SATA 3.0Gb/s

Now, i just replaced the ram, g-card, and power supply, and the origional power supply i got was DOA unfortunantly but the other day i set up my rig using my old PSU to download ETW i had been playing some stuff and occasionally it would crash, a multitude of squares at angles and in many colors could apear on the screen blocking out the view and horribly lagging the computer, it would continue to run for a few seconds very poorly then usually die and restart alltogether, i assumed it was just because my graphics card was underpowered but today i received both the game and my new power supply and im still experienceing the random crashes, quite annoying does anyone know what could cause this?

Voltage for that ram is not the standard 1.8V but 2.1V ... change the default settings to the 2.1V and you should have any memory issues go away... unless the memory is defective............

... can anone help me please im in a quite the pickle

Thanks for the help, I dled Cpu-Z but in the SPD tab its not showing the settings for 667 MHz only 200 266 and 400 MHz, was 667 Mhz correct setting for the ram or basically.. how did u get that number?

are you sure? cause it really only shows 200 266 and 400 Mhz